U.S. Pat. No. 5,788,617, entitled “Pectoralis Major and Upper Back Exerciser,” issued on Aug. 4, 1998, and is incorporated herein. The invention described therein represented a marked improvement over devices of the past, by providing two-way, spring-less resistance in a hand held exerciser. The exerciser included a joint between two hydraulic arms, each of which had an adjustable valve to permit more or less pneumatic resistance during operation.
While the invention described in the aforementioned patent had several advantages over the prior art, forces exerted by the user could cause damage to the joint between the two arms, particular when using an infinitely adjustable locking mechanism. Moreover, experience indicated that infinite positions of the arms relative to each other, between 0 and 180 degrees, does not provide any advantage that outweighs the disadvantage of having a joint that is too susceptible to weakening through use.
Thus, a need exists for an improved exercise device, for exercising the upper torso, and which is portable for use at home or on the road